William st



(No Model.)

W. ST. GEORGE ELLIOTT.

KNIFE POR MOWERS, REAPERS, dw. No. 394,349. Patented'Deo. 11, 1888.

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VILLIAM ST. lrEOlGE ELLIOTT, OF LONDON, ENGLAND.

KNIFE FOR MOWERS, REAPERS, C.

SPECIFICATION forming part of Letters Patent No. 394,349, dated December 11, 1888.

Application filed June 22, 1887. Serial No. 242,128. (No model.)

To @ZZ whom, it may concern,.-

Be it known that I., 'ILLIAM ST. GEORGE ELLIOTT, now residing in London, England, have invented eert-ain. new and uset'ul Improvements in Knives tor Mowers, Reapers, &e.; and I do hereby declare that the following is a full, clear, and exact description thereof, reference being had to the aecompw nying drawings, and to the letters ot' .reference marked thereon, which t'orm part oit' this specification.

This invention relates to certain improvef ments in knives or cutters for mowing-machines and harvesters; and its object is to improve the construction of hollow Cutters, the reeiproeation of which will keep the eutting-edges of the same constantly sharp. This I accomplish by making the cutters with hard exteriors and soft interiors, in order that the interior part ot' the cutter will wear away faster than said exterior, thereby Causing the cutters to automatically maintain good and effective edges. This object I at* tain by the means illustrated in the accompanying drawings, in whieh- Figure l represents a top vicw ot' one of the cutters ot' a harvester construeted aecording to myinvention. Fig. i? represents a transverse sectional view ot' the same on line .7: fr, Eig. l, Fig. 3 represents a top view of a modified construction ot' cutter on line ir J', Fig. Fig. 4 is a transverse sectional view ot' the same. Figs. 5 and (i represent similar views of a third modification.

Referring to the drawings by letter, A indicates the cutter, the cutting-edge ot' which is of the usual angular configuration, the body consistingl ot' a hollow or concave-convex shell, as indicated in the drawings. This euttershell is made, preferably, of sheet metal bent into the proper shape in any suitable manner; but it maybe made of east metal, if desired. The out-er side ot' the shell is case-hardened, the interior side remaining soft, so that the inner or sot'ter portions of the shell may, by abrasion, wear more rapidly than the outer hardened portion, which forms the cutting-edges ot the cutter, thereby keeping the edges sharp and keen.

Instead of Constructing the cutters of easehardened soft metal, as above described, they may be composed of an exterior thin steel shell reentoreed by an interior shell of soft metal. In some instances the steel shell may be open at the center and replaced by soft metal, as shown in Figs. 5 and f3, the ctiect ot` which will also be to preserve the exterior edge ot' the cutter.

In the drawings the cutters are shown triangular in plan; but it is evident that they may be otherwise shaped without departing` from the spirit ot' my invention, the essential features of which are, as I have said, the hollow exterior hard cutting-edge portion of the cutter and the hollow sott portion on the interior surface of the eutter.

The advantages ot' my cutter-shell over the ordinary one-quality metal cutters are obvious, in that the latter must be suiieiently heavy or thick to stand the strain incident to usage, and when so made the cutting-edge, beingl thick, will not wear uniformly, and the exterior portion of the edge will round up from wear bet'ore the interior has worn suliiciently to' keep the exterior ot' the edge in Contact with the guard-linger edges. By my invention the cutters are suliieiently strong, owing to the duetility of the interior port-ion ot' the shell, which, however, wears more rapidly than the exterior portion, and the latter portion, the edges otl which t'orm the hard cutting-ed ge, is so thin or narrow that its wear equal throughout and close contact with the guard-fingers preserved.

Having described my invention, I claim- As an improved article of manufaetm'e, a cutter for harvesters angular in plan and composed of a colicziw'o-convex shell of metal, the lower or concave portion being composed ot' softer metal than the outer or convex portion, the whole constructed substantially as described, whereby the edges ot' the cutters will be kept keen and sharp when the cutters are reeiprocateal by reason of the unequal wear of the outer and inner portions of the cutter-shell against the guard-lingers.

In testimony that I claim the foregoing as my own I ali-ix my signature in presence of t-wo witnesses.

WILLIAM S'l. GEORGE ELLIOTT.

'itnesses:

H. H. NEWMAN, G. N. MoPoLD, Consulate General, U. S. A., London. 

